TIME RESOLVED FOURIER TRANSFORM INFRARED SPECTROSCOPY

This study examined the potential of time resolved Fourier transform infrared spectroscopy as a method of investigating transient intermediates and vibrationally excited products in gas phase reactions of small organic molecules. A Michelson interferometer and a laboratory computer were used to implement a spectrometer system which can acquire time resolved infrared spectra from reproducible chemical sources. This system was used to record transient infrared radiation with a maximum time resolution of 10 microseconds from chemical reactions induced by a xenon flash lamp, a high voltage spark and a pulsed RF plasma.;Time resolved infrared spectra of flash photolysis reactions had previously been reported in the literature. These experiments were repeated, and the results which were obtained showed that the previous work was erroneous. Reactions induced by a high voltage discharge were also examined. Spectra were recorded showing time-dependent infrared emission from vibrationally excited materials formed in the spark. Preliminary experiments were conducted on reactions occurring in an RF plasma, and these indicated that future work in this area should be productive.;The need for better instrumental methods in transient infrared spectroscopy is demonstrated, and the ability of time resolved Fourier transform infrared spectroscopy to satisfy this need is discussed. The operation of the interferometer and computer in the time resolved spectrometer are described, and the effects of various experimental parameters are examined in detail. The design, implementation and testing of the spectrometer system are discussed in terms of hardware and software.